DE102005057816A1 - Switching units actuating method for use in dual clutch gearbox, involves controlling magnetic valves in gearbox such that actuators are provided with operating pressure, while connection is closed between actuators and controller - Google Patents

Abstract

The method involves arranging switching units (8, 9) to centering actuators. Piston spaces are subjected with a fluid operating pressure based on pre-control pressure that is adjusted by a pressure control valve. The spaces are provided based on an operating condition by control valves that are controlled by magnetic valves. The magnetic valves are controlled in a dual clutch gearbox (1) such that the actuators are provided with the operating pressure, while connection is closed between the actuators and controller that guides the operating pressure in the area of the control valve.

Description

The The invention relates to a method for actuating switching elements of a Dual-clutch transmission according to the im Preamble of claim 1 further defined type.

at known from practice dual-clutch transmissions are used to actuate the individual gears usually hydraulically or pneumatically operated Actuating cylinder used by means of which in manual transmissions made by a driver and required to complete a gear ratio Shift rail operations automated the translation stage provided for the presentation of the desired translation, which may for example be designed as a gear pair, in the power flow of the dual-clutch transmission.

With the shift rails are designed as synchronizations switching elements connected during the Circuits for connecting translation stages two partial transmissions in the power flow or to switch off the gear ratios are provided from the power flow. The partial transmissions themselves are each over a partial transmission associated frictional coupling in the power flow a dual-clutch gearbox switchable and have to insert the translation levels provided switching elements. Shift elements of partial transmissions in each case a double-acting actuating cylinder is assigned, whose piston chambers operating condition dependent can be acted upon with a fluidic working pressure for actuating the switching elements.

Of the Working pressure becomes dependent one over Pressure control valves adjustable pilot pressure set and with the help of over Solenoid valves controllable switching valves to the controlled piston chamber guided an actuating cylinder.

there is the operation a switching element of a switched into the power flow subtransmission mechanically locked by the corresponding actuating cylinder, if a switching element of the switched subtransmission of his associated Actuating cylinder in a switching a gear ratio Mold pressed becomes.

Around preferably To perform traction interruption-free circuits are the shift rails a dual-clutch transmission in contrast to manual transmissions or automated manual transmissions usually decoupled from each other actuated. This offers the possibility in the currently switched off from the power flow part of the transmission for setting a requested translation of the dual clutch transmission in the power flow zuzuschaltende translation stage by appropriate Pressurization of the corresponding adjusting cylinder and the associated activity of the with the actuating cylinder on the Insert shift rod operatively connected switching element. simultaneously is a drive torque of a prime mover of a motor vehicle on the switched sub-transmission in the direction of the output of the vehicle guided.

at so executed However, transmission devices disadvantageously have the possibility that in one of the partial transmission due to a faulty control, the an operation a switching element and an operatively connected switching rod another translation level entails, under certain circumstances a second gear is ansynchronisiert, whereby voltages in the Powertrain arise that destabilizes a vehicle have as a consequence.

Out this reason has been passed to a so-called inactive shift rod of a partial transmission of a Dual clutch transmission with a mechanical shift bar lock too Block when the active shift rod of the relevant sub-transmission is not in its neutral position, in the one with the Switch rod operatively connected switching element not in the for the connection the associated translation level actuated becomes. With the above-described shift rod lock is always only one gear or a translation stage can be inserted in each partial transmission.

Disadvantageously can but in such executed Driven errors in the hydraulic or pneumatic control system lead to, that in the dual clutch transmission on by a current shift request not requested gear is engaged or a currently engaged Gang or a currently switched gear ratio unwanted is designed or turned off. This leads during the operation of a motor vehicle affecting the ride comfort Force flow interruptions and component loads in unwanted Extend increasing overspeed as well too inadmissible Gang jumps.

Of the The present invention is therefore based on the object, a method to operate of switching elements of a dual-clutch transmission with mechanical To provide switching rod locking, with which Faulty control can be avoided in a simple and cost-effective manner can.

According to the invention this Task with a method having the features of claim 1 solved.

at the method according to the invention to operate of shifting elements of a dual-clutch transmission during shifting for connecting translation stages two partial transmissions in the power flow or to switch off the gear ratios are provided from the power flow, the partial transmission are about two Switching elements each over a power flow of the dual clutch transmission switchable. The partial transmissions each have at least two switching elements, which in each case at least one double-acting actuating cylinder is assigned, whose piston chambers operating condition dependent by means of Solenoid valves controllable switching valves with a depending one via pressure control valves adjustable pilot pressure stationary fluidic or hydraulic or pneumatic working pressure for actuation of the switching elements acted upon are. The operation a switching element of a switched into the power flow subtransmission is mechanical by the corresponding adjusting cylinder locked when a switching element of this sub-transmission of his associated Actuating cylinder in a switching a gear ratio Mold pressed becomes.

According to the invention the solenoid valves outside of circuits in the dual-clutch transmission so controlled that the locked actuating cylinder of the switched subgear with the working pressure is applied while the connection between the with the the translation stage schuschenden Switching element of the switched subgear cooperating Stellzylinder and a working pressure leading line in the area the switching valves is locked.

Thereby it is achieved that the actuating cylinder, during a switching operation is to be acted upon by working pressure, only during the switching of preferably each designed as a proportional valve pressure control valves actuated and the working pressure after a completed circuit is closed the mechanically locked actuating cylinder of the switched subgear guided becomes.

By the procedure according to the invention Thus, even with a fault in a hydraulic or pneumatic executed Control of the double-acting actuator cylinder inserting a switched off translation stage or designing a switched translation stage to simple and cost-effective Way avoided because a malfunction of a pressure control valve and therefore the working pressure conducted in the area of the switching valves is guided on the locked actuating cylinder.

Of Further is the procedure according to the invention without constructive changes existing hydraulic or pneumatic systems in conventional Gear devices applicable, whereby the manufacturing costs of Double clutch transmission can not be increased and thus the inventive method in a simple way with known dual-clutch transmissions can be used.

Of Further, with the method according to the invention also such called error latency, d. H. the diagnostic functions of a Transmission control unit time available to the dual-clutch transmission, extended since Faulty controls do not immediately change the translation result in the dual-clutch transmission, the appropriate countermeasures, For example, to avoid component overloads require.

Further Advantages and advantageous embodiments of the subject to The invention are the description, the drawings and the claims removed.

One embodiment the object according to the invention is schematically simplified in the drawing and will be explained in more detail in the following description.

It shows:

1 a highly schematic transmission scheme of Doppelkupp a transmission gear;

2 a hydraulic diagram of a device for actuating switching elements of the dual clutch transmission according to 1 ;

3 a schematic diagram of in 2 illustrated pressure control valves and solenoid valves outside a circuit and

4 a circuit diagram of the solenoid valves and the pressure control valves of the hydraulic scheme according to 2 of the dual-clutch transmission according to 1 ,

In 1 is a block diagram or a transmission diagram of a dual-clutch transmission 1 with two partial transmissions 2 . 3 shown, in which, depending on a respective to be set translation of the dual clutch transmission 1 a via an input shaft 4 Torque applied via the first partial transmission 2 , the second partial transmission 3 or over both partial transmissions 2 . 3 on an output shaft 5 to be led.

The dual-clutch transmission 1 is preferably used in vehicles, wherein an outgoing drive of a non-illustrated engine drive torque from the Eingangswel le 4 via the dual-clutch transmission 1 on the output shaft 5 and thus led to an output of the vehicle.

The dual-clutch transmission 1 With appropriate control at the transmission input, a power split of the input torque to two power branches 6 . 7 on, wherein in the first power branch 6 the first partial transmission 2 and in the second power branch 7 the second partial transmission 3 is arranged. Each of the power branches 6 . 7 is each with a switching element 8th respectively. 9 executed, by means of which the partial transmission 2 and 3 each in a power flow of the dual clutch transmission 1 can be switched or switched off from this.

The two partial transmissions 2 and 3 are presently designed such that in each partial transmission 2 . 3 four different gear ratios are switchable. With this version of the two partial transmissions 2 . 3 and the switching elements 8th . 9 are in combination with the switching logic described below many gear ratios and overall ratios of the dual clutch transmission 1 adjustable with a very small number of gear ratios.

The design of the three gears 2 and 3 each with four partial translations offers in this case in conjunction with a suitable control of the switching elements 8th and 9 the possibility of representing a total of eight gear steps, with seven gear steps representing so-called forward driving steps and the eighth gear step is a reverse gear.

The eight gear steps and the corresponding switching logic as well as the required control of the dual-clutch transmission is using a dual-clutch transmission 1 associated hydraulic system, of which in 2 a part is shown as a hydraulic scheme carried out. Furthermore, the required to represent the eight-speed switching logic and the required thereby driving the dual-clutch transmission is schematically in 3 and 4 each shown as a circuit diagram, wherein the in 3 Table in conjunction with 1 and 2 to help clarify the described procedure according to the invention.

About the hydraulic system of the dual-clutch transmission 1 are in 2 Not shown in detail and in the tabulated circuit diagrams according to 3 and 4 listed switching elements A, B, C, D, E, F, G and H operable. The switching elements A to H are in the in 1 illustrated embodiment of a dual-clutch transmission designed as conventional synchronizers, by means of which speed differences between rotating shafts and over the synchronizations with the waves to be connected gear pairs are compensated in a conventional manner.

Each of the switching elements A to H to be actuated here is a double-acting actuating cylinder 10 . 11 . 12 and 13 assigned to their piston chambers 10A . 10B . 11A . 91B . 12A . 12B . 13A and 13B operating state dependent can be acted upon by valves with hydraulic working pressure. There are two gear valves for adjusting the hydraulic working pressure 14 . 15 each provided with a pressure control valve designed as a proportional valve 16 respectively. 17 adjustable pilot pressure p_VS_14 or p_VS_15 can be acted upon.

The gear valves 14 and 15 are presently designed as pressure control valves, in which of the gear valves 14 and 15 set hydraulic pressure for pressure control in each case on an effective surface of a valve spool 14_S respectively. 15_S is applied. The valve spool 14_S respectively. 15_S lock at pressures of working pressure greater than that of the gear valves 14 respectively. 15 currently to be set working pressure, the connection between a related to a system pressure p_sys supply control tongue 14A respectively. 15A and one of the gear valves 14 and 15 downstream distributor switching valve 18 ,

Downstream of the distributor switching valve 18 are three switching valves 19 . 20 and 21 provided by means of which of the gear valves 14 and 15 set working pressure operating state-dependent to the piston chambers 10A to 13B the double-acting actuator cylinder 10 to 13 is feasible. Furthermore, there are three solenoid valves 22 . 23 and 24 represented, which via an electrical transmission control device of the dual clutch transmission 1 are electrically actuated, according to their execution in energized state are open or closed and in each case the switching valves 19 to 21 or the distributor switching valve 18 are assigned to the switching valves 19 to 21 or the distributor switching valve 18 with a control state-dependent variable pilot pressure p_VS_19, p_VS_20, p_VS_21 or p_VS_18 to control.

At the pressure control valves 16 and 17 as well as on the solenoid valves 22 to 24 is a control pressure p_red, the active with the transmission control device in response to the energization of the pressure control valves 16 and 17 as well as the solenoid valves 22 to 24 accordingly converted as pilot pressure p_VS the switching valves 19 to 21 , the distributor switching valve 18 and the gear valves 14 and 15 is supplied.

In addition, two designed as a plate valves pressure relief valves 25 and 26 in front Seen, by means of which in the hydraulic system, the dual-clutch transmission 1 a so-called Vorbefülldruck is maintained in order to avoid the entry of air into the hydraulic line system.

The double-acting actuators 10 to 13 are basically identical and each with a piston 10C . 11C . 12C or 13C and an associated shift rod 10D . 11D . 12D or 13D executed, so that in dependence of in the piston spaces 10A and 10B . 11A and 11B . 12A and 12B or 13A and 13B set working pressures hydraulic energy in a translational actuation movement for the shift rails 10D to 13D is convertible to actuate the connected to the shift rails in a manner not shown switching elements A to H accordingly.

In this case, it is provided that via the actuating cylinder 10 depending on the position of the piston 10C who in 2 is shown in its preferred neutral center position, either the switching element G or the switching element H is actuated. This is the piston 10C proceeding from its neutral center position in which neither the switching element G nor the switching element H is operated to move into its first end position or in its second end position.

About the actuating cylinder 11 Either the switching element E or the switching element F in the same manner as in the actuating cylinder 10 by appropriate pressurization of the two piston chambers 11A and 11B actuated. The actuating cylinder 12 is provided for actuating the switching element A or the switching element B, while by means of the actuating cylinder 13 the switching element C or the switching element D can be actuated.

In the first column of the table of in 3 shown switching logic of the dual clutch transmission 1 , which represents the states of the components outside of circuits in the dual-clutch transmission, are each in the dual-clutch transmission 1 producible states or grades listed, with the letter "N" a neutral operating state of the dual clutch transmission 1 is designated, in which the power flow of the Antriebsstran ges of a vehicle in the region of the dual clutch transmission 1 is interrupted and the output is decoupled from the prime mover.

in the Operating state "P", the park operating state corresponds, the power flow of the drive train is also in Area of the dual-clutch transmission interrupted, with the output in the present case in a manner known per se by a parking brake is held against rotation.

In the columns 2 to 4 is each the driving state of the solenoid valves 22 to 24 and in the fifth and sixth columns, the driving state of the pressure control valves 16 and 17 played. In the columns 7 and 8th are the switching states of the switching elements 8th . 9 graphed while in the columns 9 to 16 the switching states of the switching elements A to H are reproduced.

The active states of the solenoid valves are 22 to 24 and the pressure control valves 16 and 17 and the switching states of the switching elements 8th . 9 or the switching elements A to H respectively indicated by the fact that in the individual cells of the table, an active valve or a switched switching element is characterized by a black dot and a nichtschaltaltetes switching element or an inactive valve each having a free cell. Furthermore, circuits in the area of the switching elements A to H are provided in different cells, each with a white surface. With the circles, the switching elements A to H are marked, each in a partial transmission 2 or 3 already before the connection of the partial transmission 2 or 3 in the power flow of the dual-clutch transmission 1 are pre-selected for a requested by a shift request gear in a conventional manner.

This in 4 Schematic diagram is opposite to in 3 Shown circuit diagram shown shortened, wherein in the first column, the switching elements A to H are listed. In the columns 2 to 6 are the activation states of the solenoid valves provided during a shift in the dual-clutch transmission 22 to 24 and the pressure control valves 16 and 17 an activated valve is characterized in each case by a black dot in a cell of the table and inactive valves or non-energized valves are characterized by free cells.

How out 3 it can be seen are to set a first forward gear or gear ratio "1" of the dual clutch transmission 1 the switching element 8th of the first power branch 6 and the switching element D of the first partial transmission 2 and the switching element H of the second partial transmission 3 closed. The switching element 9 of the second power branch 7 it is open. At the same time, all three solenoid valves 22 to 24 energized while the pressure control valves 16 and 17 are switched off by the gearbox control unit.

With engaged second gear "2" are also all solenoid valves 22 to 24 active and the switching element 9 of the second power branch 7 is closed in addition to the switching element H, while the switching element D of the first sub-transmission 2 For a possible downshift in the first gear "1" and / or the switching element B for a possible upshift in the third gear "3" with the switching element open 8A can be inserted.

From the wiring diagram according to 3 goes on to show that the pressure control valves 16 and 17 basically are not energized outside of circuits, which is why the pilot pressures p_VS_14 and p_VS_15 the gear valves 14 and 15 are essentially zero. This causes the gear valves 14 and 15 due to the output side of the service valve applied working pressure of the actuating cylinder 10 to 13 switch over against the pilot pressure p_VS_14 or p_VS_15 and the system pressure p_sys from the downstream of the gear valves 14 and 15 arranged part of the hydraulic system of the dual clutch transmission 1 is disconnected.

The respectively for the currently in the dual-clutch transmission 1 engaged gear ratio "R" or "1" to "7" is also with closed gear valves 14 and 15 due to the structural design of the switching elements A to H without further pressurization of the piston chambers 10A to 13B the actuating cylinder 10 to 13 held.

At the transmission control device is a shift request to change from a currently in the dual-clutch transmission 1 In the engaged gear stages in a higher or a lower gear stage or from a forward gear in the reverse gear or in the neutral operating state or the parking operating state before, the switching elements A to H via the solenoid valves 22 to 24 and the pressure control valves 16 and 17 according to the in 4 controlled manner shown. This means that the control or actuation of the switching element A, the solenoid valve 24 and the pressure control valve 17 be energized so that the piston chamber 12B of the adjusting cylinder 12 via the distributor switching valve 18 , the switching valve 20 and the switching valve 21 is acted upon by working pressure, wherein the solenoid valves 22 and 23 not be energized for this purpose.

The pressurization of the piston chamber 12B of the adjusting cylinder 12 causes the piston 12C together with the fixedly connected shift rod D, starting from its neutral position in the direction of the piston chamber 12B is moved to a stop, wherein the synchronization or the switching element A inserted and a switching element A associated translation stage of the first sub-transmission 2 is activated.

By adjusting the piston 12C or the shift rod 12D becomes the shift rod 13D of the adjusting cylinder 13 in the neither the switching element C nor the switching element D actuated neutral position mechanically locked in a conventional manner to a simultaneous connection of two gear ratios in partial transmission 3 to avoid in a simple way.

The means that with a actuator-side actuation of a Shift rod one actuation each another shift rod of the same sub-transmission by a mechanical Locking the other shift rod in its neutral position is prevented and the operatively connected to the other switching rod Switching elements can not be actuated by hydraulic working pressure.

The well-known approach of mechanically locking a not active in the representation of a in the dual-clutch transmission 1 inserted translation of a sub-transmission is used in the proposed method according to the invention in the manner described below:
After completion of a circuit, either the energized pressure control valve 16 or the energized pressure control valve 17 de-energized, leaving the gear valve 14 or the gear valve 15 is no longer supplied with pilot pressure p_VS_14 or p_VS_15 and the supply of the downstream of the gear valves 14 and 15 arranged part of the hydraulic system with system pressure p_sys in the range of the gear valves 14 and 15 is interrupted.

At the same time, the switching valves 19 . 20 and 21 from the solenoid valves 22 and 23 so controlled that the downstream of the valves 14 and 15 present in the hydraulic system pressure, which during the circuit at one operatively connected to the operable for the implementation of the circuit switching element A to H actuating cylinder 10 . 11 . 12 or 13 is present, a piston chamber of the actuating cylinder of the currently engaged in the dual-clutch transmission ratio in the power flow switched subtransmission 2 or 3 is supplied, the shift rod is mechanically held by the actuation of the shift rod of the other actuating cylinder in its neutral position.

This ensures that the representation of the in the dual-clutch transmission 1 currently engaged translation or gear stage actuated switching element due to a faulty control of the pressure control valves 16 or 17 not designed. At the same time, an unwanted insertion of a gear ratio of the switched-off sub-transmission is also 2 or 3 avoided, since the working pressure is performed during a circuit and also outside of circuits in any case in the direction of the actuating cylinder, the shift rod is mechanically locked.

As an alternative to the above-described embodiment, it is in a further advantageous embodiment of the invention Vorrich tion provided that the actuating cylinder for actuating the switching elements are pneumatically controlled.

1

Double clutch

2

first subtransmissions

3

second subtransmissions

4

input shaft

5

output shaft

6

first power branch

7

second power branch

8th

switching element

9

switching element

10 to 13

actuating cylinder

10A to 13B

piston chamber

10C to 13C

piston

10D to 13D

piston rod

14 15

Globe valve

14A, 15A

Supply control tongue

14_S, 15_S

valve slide

16 17

Pressure control valve

18

Distributor switching valve

19 until 21

switching valve

22 to 24

magnetic valve

25 26

magnetic valve

"1" to "7"

Grade, Forward gear

A to H

switching element

"N"

Neutral mode

"P"

Park mode

"R"

Grade, Reverse gear

p_VS

pilot pressure

p_sys

system pressure

pressure P_Red

control pressure

Claims (7)

Method for actuating switching elements (A to H) of a dual-clutch transmission ( 1 ), which during circuits for connecting transmission stages of two partial transmissions ( 2 . 3 ) are provided in the power flow or for switching off the gear ratios from the power flow, wherein the partial transmission ( 2 . 3 ) via two switching elements ( 8th . 9 ) in each case in a power flow of the dual-clutch transmission ( 1 ) are switchable and each have at least two switching elements (A to H), which in each case at least one double-acting actuating cylinder ( 10 to 13 ) whose piston chambers ( 10A to 13B ) operating state-dependent by means of solenoid valves ( 22 . 23 . 24 ) controllable switching valves ( 19 . 20 . 21 ) with a function of a pressure control valves ( 16 . 17 ) adjustable pilot pressure (p_VS_14, p_VS_15) fluid pressure for actuation of the switching elements (A to H) are acted upon, and wherein the actuation of a switching element (A to H) of a switched into the power flow subtransmission ( 2 . 3 ) by the corresponding adjusting cylinder ( 10 to 13 ) is mechanically locked when a switching element (A to H) of this sub-transmission ( 2 . 3 ) from its associated actuating cylinder ( 10 to 13 ) is actuated in a gearshifting to a translation stage, characterized in that the solenoid valves ( 22 . 23 . 24 ) outside of circuits in the dual-clutch transmission ( 1 ) are controlled such that the locked actuating cylinder ( 10 to 13 ) of a connected sub-transmission ( 2 . 3 ) is applied to the working pressure, while the Vefrbindung between the switching stage with the switching element switching element (A to H) of the engaged sub-transmission ( 2 . 3 ) co-operating actuating cylinder ( 10 to 13 ) and a working pressure line leading in the field of switching valves ( 19 to 21 ) Is blocked. A method according to claim 1, characterized in that via the pressure control valves ( 16 . 17 ) adjustable pilot pressure (p_VS_14, p_VS_15) outside a circuit is substantially reduced to zero. A method according to claim 1 or 2, characterized in that the pilot pressure (p_VS_14, p_VS_15) of the pressure control valves ( 16 . 17 ) each on an active surface of a valve spool ( 14_S . 15_S ) designed as a pressure control valve gear valves ( 14 . 15 ). A method according to claim 3, characterized in that at the gear valves ( 14 . 15 ) a supply pressure (p_sys) is applied, which depends on the pilot pressure (p_VS_14, p_VS_15) of the pressure control valves ( 16 . 17 ) is transformed in the required for the actuation of the switching elements (A to H) working pressure. A method according to claim 3 or 4, characterized in that via the passage valves ( 14 . 15 ) regulated working pressure in response to a switching position of a valve spool one of the solenoid valves ( 24 ) controllable distributor switching valve ( 18 ) taking into account a requested gear ratio in the direction of one of a plurality of the distributor switching valve ( 18 ) downstream switching valves ( 19 to 21 ) to be led. Method according to one of claims 1 to 5, characterized that the actuating cylinders are pneumatically operated. Method according to one of claims 1 to 5, characterized in that the actuating cylinder ( 10 to 13 ) are hydraulically operated.